[[TitleIndustry]]

Lead storage battery, lithium battery and Power Battery

Date:Apr 18, 2019

Lead storage battery is one of the power batteries. Its function is to store limited electric energy and use it in a suitable place. It works by converting chemical energy into electrical energy. It uses a lead plate filled with sponge lead as a negative electrode, a lead plate filled with lead dioxide as a positive electrode, and 22 to 28% of dilute sulfuric acid as an electrolyte. When charging, electrical energy is converted into chemical energy, which is converted into electrical energy during discharge. When the battery is discharged, the metal lead is a negative electrode, which undergoes an oxidation reaction and is oxidized to lead sulfate; the lead dioxide is a positive electrode, and a reduction reaction occurs, and is reduced to lead sulfate. When the battery is charged by direct current, the two poles respectively produce lead and lead dioxide. After removing the power supply, it returns to the state before discharge to form a chemical battery. A lead storage battery is a battery that can be repeatedly charged and discharged, and is called a secondary battery. Its voltage is 2V, usually three lead batteries are used in series, the voltage is 6V. The car uses six lead batteries in series to form a 12V battery pack.


A lithium battery is a type of battery using a lithium metal or a lithium alloy as a negative electrode material and using a nonaqueous electrolyte solution. Due to the very active chemical properties of lithium metal, the processing, storage and use of lithium metal are very demanding on the environment. Therefore, lithium batteries have not been used for a long time. With the development of microelectronics technology in the twentieth century, the number of miniaturized devices is increasing, and high requirements are placed on power supplies. Lithium batteries have entered a large-scale practical stage.


What is the connection between the power battery and the lithium battery?


According to the chemical type, the battery can be divided into lead-acid battery, primary alkaline battery, nickel-cadmium battery, nickel-hydrogen battery, lithium-ion battery and so on. The battery can be divided into a power battery and an ordinary battery according to the discharge current that can be outputted. The difference between the power battery and the ordinary battery is basically defined as: the ordinary battery can be discharged at a maximum current of 3C, and the power battery generally refers to a current discharged at 5C, and An ultra-high power battery can discharge at a current of 20C or more.


Therefore, lithium batteries have both a normal type and a power type. There are lead-acid batteries in the power battery, nickel-hydrogen batteries, and lithium-ion batteries.


What is the difference between a power lithium battery and a consumer lithium battery from the perspective of research and development?


Power lithium-ion batteries need more consideration for reliability and consistency. After all, it takes a long time (at least 5~10 years), harsh environment (low temperature in winter, summer exposure, rain and snow), and a large number of batteries are connected in series. Considering reliability and consistency, assuming that a car uses 1000 power batteries, ideally, car manufacturers hope that there will be no problem under the scale of a model of 100,000 vehicles, that is, the probability that the power battery is ideally required to be in one Less than one billionth. Considering reliability, power batteries are generally designed to be more redundant, using thicker diaphragms, foils and casings, so the energy density is about half that of consumer batteries.


Consumer lithium-ion batteries do not require long-term reliability, and generally do not need to be used separately. Therefore, there is not much requirement for consistency, but since consumer mobile phones and pads have limited space and are very precious, consumer lithium-ion batteries are for size. Strict requirements, capacity, energy density, etc. are very demanding.


For safety, the power battery has more external protection circuits, thermal layout, etc., of course, it faces more severe conditions (higher external voltage, higher current, more complicated external environment), consumer battery protection. Less, relying on the material and design of the battery on a higher energy density to withstand various safety-critical situations.


High-end consumer batteries use state-of-the-art technology and materials, while power batteries require advanced process control, consistency control, and quality management.


1. The capacity is different, and the power of the general large mobile phones and other electronic products has a small capacity.

2. The cycle life power will also be high.

3. At the temperature control point, the power will have a protective temperature of the battery pack.


What is the difference between a power lithium battery and a capacity lithium battery?


There are many types of lithium batteries, such as power lithium batteries and capacity lithium batteries, so what is the difference between these two lithium batteries?


1, the voltage is different


In the battery industry, the voltage is increased, and the corresponding output voltage is also increased, so that the power type lithium battery pack can satisfy some high-power devices; and the parallel mode directly affects the current of the entire battery pack. Increase, and the capacity is affected by the current at the output, so the direct effect of the parallel is to increase the capacity of the lithium battery pack. The capacity of the battery pack connected in this way tends to be relatively large, so-called capacity lithium. Battery.


2, the application of the product is different


Some large devices require a higher voltage value because a low-power battery pack does not work, so a power lithium battery pack is required. For example, the electric bicycles we usually use, the voltage value required by them is often 48V. Compared with some situations in our lives, 48V is not too small. Therefore, it is necessary to use a power type lithium battery pack to ensure the operation of the electric bicycle. And we usually go to some large supermarkets or shopping malls, some sign lights and backup power, because these devices do not consume a lot of power, so they generally use capacity lithium battery packs, which are different in product application. of.


3, the internal resistance is different


The internal resistance of the power lithium battery is smaller than that of the capacity lithium battery. Taking 18650 as an example, a good manufacturer with a 3 times rate discharge generally has a PDC, and the internal resistance is about 40; the 5 times rate discharge generally does not have a PDC internal resistance 20 about.


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